With the development of the automobile industry, energy shortage and environmental pollution is a growing concern. The manufacturers and research institutions have been committed to effectively use energy in the operation of vehicles, especially the recycling of energy. Converting the kinetic energy into electrical energy is the mainstream research and development direction, but because of low efficiency of the conversion the result is always unsatisfactory. At the same time, the research on the conversion of potential energy into kinetic energy has been neglected. Although the negative pressure energy generated in the engine suction process is utilize the in prior art, the magnitude of this energy can only be controlled by changing the power of the engine. So this potential energy is not used conveniently and efficiently.